yup

concat doesn't check for "unset" nullable or presence when merging meaning the nullability and presence will always be the same as the schema passed to concat(). They can be overridden if needed after concatenation

Schema factory functions are no longer constructors. The classes are now also exported for extension or whatever else. e.g. import { StringSchema, string } from 'yup'

array().required() will no longer consider an empty array missing and required checks will pass.

Plain objects and arrays are no long cast to strings automatically

defined() now doesn't automatically allow null, this was a bug. to mimic the old behavior add nullable() to schema with defined()

Update docs to account for changes in types and add additional example (#891) (e105a71), closes #891

For users of @types/yup only, no function changes but the type def change is large enough that it warranted a major bump here

Deprecate the getter overload of default()